A 61-year-old woman with hyperthyroidism is treated with propylthiouracil. The drug reduces the synthesis of thyroid hormones because it inhibits oxidation of
(A) Triiodothyronine (T3 )
(B) Thyroxine (T4 )
(C) Diiodotyrosine (DIT)
(D) Thyroid-stimulating hormone (TSH) (e) Iodide (I− )
Propylthiouracil (PTU) is an antithyroid medication that primarily works by inhibiting the enzyme thyroid peroxidase, which is involved in the oxidation of iodide to iodine and the coupling of iodotyrosines to form thyroid hormones.
In this context, the correct answer is:
(E) Iodide (I−)
By inhibiting the oxidation of iodide, PTU reduces the synthesis of thyroid hormones (T3 and